mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-22 19:00:07 +00:00
162 lines
4.9 KiB
C
162 lines
4.9 KiB
C
/* Locate the shared object symbol nearest a given address.
|
|
Copyright (C) 1996-2015 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
The GNU C Library is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library; if not, see
|
|
<http://www.gnu.org/licenses/>. */
|
|
|
|
#include <dlfcn.h>
|
|
#include <stddef.h>
|
|
#include <ldsodefs.h>
|
|
|
|
|
|
static inline void
|
|
__attribute ((always_inline))
|
|
determine_info (const ElfW(Addr) addr, struct link_map *match, Dl_info *info,
|
|
struct link_map **mapp, const ElfW(Sym) **symbolp)
|
|
{
|
|
/* Now we know what object the address lies in. */
|
|
info->dli_fname = match->l_name;
|
|
info->dli_fbase = (void *) match->l_map_start;
|
|
|
|
/* If this is the main program the information is incomplete. */
|
|
if (__builtin_expect (match->l_name[0], 'a') == '\0'
|
|
&& match->l_type == lt_executable)
|
|
info->dli_fname = _dl_argv[0];
|
|
|
|
const ElfW(Sym) *symtab
|
|
= (const ElfW(Sym) *) D_PTR (match, l_info[DT_SYMTAB]);
|
|
const char *strtab = (const char *) D_PTR (match, l_info[DT_STRTAB]);
|
|
|
|
ElfW(Word) strtabsize = match->l_info[DT_STRSZ]->d_un.d_val;
|
|
|
|
const ElfW(Sym) *matchsym = NULL;
|
|
if (match->l_info[DT_ADDRTAGIDX (DT_GNU_HASH) + DT_NUM + DT_THISPROCNUM
|
|
+ DT_VERSIONTAGNUM + DT_EXTRANUM + DT_VALNUM] != NULL)
|
|
{
|
|
/* We look at all symbol table entries referenced by the hash
|
|
table. */
|
|
for (Elf_Symndx bucket = 0; bucket < match->l_nbuckets; ++bucket)
|
|
{
|
|
Elf32_Word symndx = match->l_gnu_buckets[bucket];
|
|
if (symndx != 0)
|
|
{
|
|
const Elf32_Word *hasharr = &match->l_gnu_chain_zero[symndx];
|
|
|
|
do
|
|
{
|
|
/* The hash table never references local symbols so
|
|
we can omit that test here. */
|
|
if ((symtab[symndx].st_shndx != SHN_UNDEF
|
|
|| symtab[symndx].st_value != 0)
|
|
&& ELFW(ST_TYPE) (symtab[symndx].st_info) != STT_TLS
|
|
&& DL_ADDR_SYM_MATCH (match, &symtab[symndx],
|
|
matchsym, addr)
|
|
&& symtab[symndx].st_name < strtabsize)
|
|
matchsym = (ElfW(Sym) *) &symtab[symndx];
|
|
|
|
++symndx;
|
|
}
|
|
while ((*hasharr++ & 1u) == 0);
|
|
}
|
|
}
|
|
}
|
|
else
|
|
{
|
|
const ElfW(Sym) *symtabend;
|
|
if (match->l_info[DT_HASH] != NULL)
|
|
symtabend = (symtab
|
|
+ ((Elf_Symndx *) D_PTR (match, l_info[DT_HASH]))[1]);
|
|
else
|
|
/* There is no direct way to determine the number of symbols in the
|
|
dynamic symbol table and no hash table is present. The ELF
|
|
binary is ill-formed but what shall we do? Use the beginning of
|
|
the string table which generally follows the symbol table. */
|
|
symtabend = (const ElfW(Sym) *) strtab;
|
|
|
|
for (; (void *) symtab < (void *) symtabend; ++symtab)
|
|
if ((ELFW(ST_BIND) (symtab->st_info) == STB_GLOBAL
|
|
|| ELFW(ST_BIND) (symtab->st_info) == STB_WEAK)
|
|
&& ELFW(ST_TYPE) (symtab->st_info) != STT_TLS
|
|
&& (symtab->st_shndx != SHN_UNDEF
|
|
|| symtab->st_value != 0)
|
|
&& DL_ADDR_SYM_MATCH (match, symtab, matchsym, addr)
|
|
&& symtab->st_name < strtabsize)
|
|
matchsym = (ElfW(Sym) *) symtab;
|
|
}
|
|
|
|
if (mapp)
|
|
*mapp = match;
|
|
if (symbolp)
|
|
*symbolp = matchsym;
|
|
|
|
if (matchsym)
|
|
{
|
|
/* We found a symbol close by. Fill in its name and exact
|
|
address. */
|
|
lookup_t matchl = LOOKUP_VALUE (match);
|
|
|
|
info->dli_sname = strtab + matchsym->st_name;
|
|
info->dli_saddr = DL_SYMBOL_ADDRESS (matchl, matchsym);
|
|
}
|
|
else
|
|
{
|
|
/* No symbol matches. We return only the containing object. */
|
|
info->dli_sname = NULL;
|
|
info->dli_saddr = NULL;
|
|
}
|
|
}
|
|
|
|
|
|
int
|
|
internal_function
|
|
_dl_addr (const void *address, Dl_info *info,
|
|
struct link_map **mapp, const ElfW(Sym) **symbolp)
|
|
{
|
|
const ElfW(Addr) addr = DL_LOOKUP_ADDRESS (address);
|
|
int result = 0;
|
|
|
|
/* Protect against concurrent loads and unloads. */
|
|
__rtld_lock_lock_recursive (GL(dl_load_lock));
|
|
|
|
struct link_map *l = _dl_find_dso_for_object (addr);
|
|
|
|
if (l)
|
|
{
|
|
determine_info (addr, l, info, mapp, symbolp);
|
|
result = 1;
|
|
}
|
|
|
|
__rtld_lock_unlock_recursive (GL(dl_load_lock));
|
|
|
|
return result;
|
|
}
|
|
libc_hidden_def (_dl_addr)
|
|
|
|
/* Return non-zero if ADDR lies within one of L's segments. */
|
|
int
|
|
internal_function
|
|
_dl_addr_inside_object (struct link_map *l, const ElfW(Addr) addr)
|
|
{
|
|
int n = l->l_phnum;
|
|
const ElfW(Addr) reladdr = addr - l->l_addr;
|
|
|
|
while (--n >= 0)
|
|
if (l->l_phdr[n].p_type == PT_LOAD
|
|
&& reladdr - l->l_phdr[n].p_vaddr >= 0
|
|
&& reladdr - l->l_phdr[n].p_vaddr < l->l_phdr[n].p_memsz)
|
|
return 1;
|
|
return 0;
|
|
}
|